There are fictional families that are enchantingly absorbing, each member capable of upholding his or her responsibility to keep matters lively, including during the course of a series of novels.

And then there’s the extended family of Detective Chief Superintendent Simon Serrailler, and his fraught love life, both of which in Susan Hill’s seventh crime novel in the run, are getting to be irritating distractions from the real event.

In A Question of Identity, that real event is the strangling deaths of elderly women, starting in a newly built community for seniors named Duchess of Cornwell Close.

The intruder apparently has had easy access to the new homes into which the elderly are just beginning to move, and a grotesque way of presenting his victims should narrow possible suspects.

But the Lafferton police investigation, led by Serrailler, is left flailing after one or two suspects turn out to be impossible as culprits.

Readers, by contrast, have more clues to work with, since the voice of the killer, and hints of his circumstances, are scattered throughout the novel — which begins with the highly controversial acquittal a decade back of a suspect in the strangulation murders of seniors in a distant part of England.

That man was then-32-year-old builder Alan Keyes and his acquittal was greeted with such hostility that he was spirited away by police, drilled in the details of a new identity, and sent to live elsewhere, supposedly supervised in his new life.

There are puzzles here.

One would be the lack of a simple computer search for similar crimes in the country that would at least tell police they weren’t dealing with a newcomer to murder, and would immediately provide photographs, as well.

Another puzzle would be why police in 2002 went to such efforts to create and then adamantly and fatally protect the new identity of a man they firmly believed guilty of cruel, gruesome murders of the helpless elderly.

And there’s Serrailler’s carelessness, not remarked upon in the novel, in not protecting a down-at-the-heels man who has obviously, to any reader, put himself in harm’s way.

Of course as must be the case, the culprit is nailed, albeit in cumbersome fashion and to no great reader surprise.

Meanwhile, Serrailler’s family members have been conducting their own dramas.

His sister Cat, widowed mother of three and a hospice physician, is losing much of her job thanks to budget cutbacks, and her sullen teenage son has taken to viciously tormenting his sister.

The marriage of Simon and Cat’s cold father and beloved step-mother appears to be in trouble.

And Simon is struggling with his own affair with a woman whose husband is dying.

After six previous novels with the same people persistently nosing about in each other’s lives, they have largely lost, sadly, the charms and interest they once had.

Susan Hill is a much-respected writer who has dealt not only in crime but in award-winning general and children’s fiction, as well as the odd ghost story.